1 // SPDX-License-Identifier: GPL-2.0
2 #include <sys/time.h>
3 #include <sys/prctl.h>
4 #include <errno.h>
5 #include <limits.h>
6 #include <time.h>
7 #include <stdlib.h>
8 #include <linux/zalloc.h>
9 #include <linux/err.h>
10 #include <perf/cpumap.h>
11 #include <perf/evlist.h>
12 #include <perf/mmap.h>
13
14 #include "debug.h"
15 #include "parse-events.h"
16 #include "evlist.h"
17 #include "evsel.h"
18 #include "thread_map.h"
19 #include "record.h"
20 #include "tests.h"
21 #include "util/mmap.h"
22 #include "util/sample.h"
23 #include "pmus.h"
24
spin_sleep(void)25 static int spin_sleep(void)
26 {
27 struct timeval start, now, diff, maxtime;
28 struct timespec ts;
29 int err, i;
30
31 maxtime.tv_sec = 0;
32 maxtime.tv_usec = 50000;
33
34 err = gettimeofday(&start, NULL);
35 if (err)
36 return err;
37
38 /* Spin for 50ms */
39 while (1) {
40 for (i = 0; i < 1000; i++)
41 barrier();
42
43 err = gettimeofday(&now, NULL);
44 if (err)
45 return err;
46
47 timersub(&now, &start, &diff);
48 if (timercmp(&diff, &maxtime, > /* For checkpatch */))
49 break;
50 }
51
52 ts.tv_nsec = 50 * 1000 * 1000;
53 ts.tv_sec = 0;
54
55 /* Sleep for 50ms */
56 err = nanosleep(&ts, NULL);
57 if (err == EINTR)
58 err = 0;
59
60 return err;
61 }
62
63 struct switch_tracking {
64 struct evsel *switch_evsel;
65 struct evsel *cycles_evsel;
66 pid_t *tids;
67 int nr_tids;
68 int comm_seen[4];
69 int cycles_before_comm_1;
70 int cycles_between_comm_2_and_comm_3;
71 int cycles_after_comm_4;
72 };
73
check_comm(struct switch_tracking * switch_tracking,union perf_event * event,const char * comm,int nr)74 static int check_comm(struct switch_tracking *switch_tracking,
75 union perf_event *event, const char *comm, int nr)
76 {
77 if (event->header.type == PERF_RECORD_COMM &&
78 (pid_t)event->comm.pid == getpid() &&
79 (pid_t)event->comm.tid == getpid() &&
80 strcmp(event->comm.comm, comm) == 0) {
81 if (switch_tracking->comm_seen[nr]) {
82 pr_debug("Duplicate comm event\n");
83 return -1;
84 }
85 switch_tracking->comm_seen[nr] = 1;
86 pr_debug3("comm event: %s nr: %d\n", event->comm.comm, nr);
87 return 1;
88 }
89 return 0;
90 }
91
check_cpu(struct switch_tracking * switch_tracking,int cpu)92 static int check_cpu(struct switch_tracking *switch_tracking, int cpu)
93 {
94 int i, nr = cpu + 1;
95
96 if (cpu < 0)
97 return -1;
98
99 if (!switch_tracking->tids) {
100 switch_tracking->tids = calloc(nr, sizeof(pid_t));
101 if (!switch_tracking->tids)
102 return -1;
103 for (i = 0; i < nr; i++)
104 switch_tracking->tids[i] = -1;
105 switch_tracking->nr_tids = nr;
106 return 0;
107 }
108
109 if (cpu >= switch_tracking->nr_tids) {
110 void *addr;
111
112 addr = realloc(switch_tracking->tids, nr * sizeof(pid_t));
113 if (!addr)
114 return -1;
115 switch_tracking->tids = addr;
116 for (i = switch_tracking->nr_tids; i < nr; i++)
117 switch_tracking->tids[i] = -1;
118 switch_tracking->nr_tids = nr;
119 return 0;
120 }
121
122 return 0;
123 }
124
process_sample_event(struct evlist * evlist,union perf_event * event,struct switch_tracking * switch_tracking)125 static int process_sample_event(struct evlist *evlist,
126 union perf_event *event,
127 struct switch_tracking *switch_tracking)
128 {
129 struct perf_sample sample;
130 struct evsel *evsel;
131 pid_t next_tid, prev_tid;
132 int cpu, err;
133
134 perf_sample__init(&sample, /*all=*/false);
135 if (evlist__parse_sample(evlist, event, &sample)) {
136 pr_debug("evlist__parse_sample failed\n");
137 err = -1;
138 goto out;
139 }
140
141 evsel = evlist__id2evsel(evlist, sample.id);
142 if (evsel == switch_tracking->switch_evsel) {
143 next_tid = evsel__intval(evsel, &sample, "next_pid");
144 prev_tid = evsel__intval(evsel, &sample, "prev_pid");
145 cpu = sample.cpu;
146 pr_debug3("sched_switch: cpu: %d prev_tid %d next_tid %d\n",
147 cpu, prev_tid, next_tid);
148 err = check_cpu(switch_tracking, cpu);
149 if (err)
150 goto out;
151 /*
152 * Check for no missing sched_switch events i.e. that the
153 * evsel->core.system_wide flag has worked.
154 */
155 if (switch_tracking->tids[cpu] != -1 &&
156 switch_tracking->tids[cpu] != prev_tid) {
157 pr_debug("Missing sched_switch events\n");
158 err = -1;
159 goto out;
160 }
161 switch_tracking->tids[cpu] = next_tid;
162 }
163
164 if (evsel == switch_tracking->cycles_evsel) {
165 pr_debug3("cycles event\n");
166 if (!switch_tracking->comm_seen[0])
167 switch_tracking->cycles_before_comm_1 = 1;
168 if (switch_tracking->comm_seen[1] &&
169 !switch_tracking->comm_seen[2])
170 switch_tracking->cycles_between_comm_2_and_comm_3 = 1;
171 if (switch_tracking->comm_seen[3])
172 switch_tracking->cycles_after_comm_4 = 1;
173 }
174
175 err = 0;
176 out:
177 perf_sample__exit(&sample);
178 return err;
179 }
180
process_event(struct evlist * evlist,union perf_event * event,struct switch_tracking * switch_tracking)181 static int process_event(struct evlist *evlist, union perf_event *event,
182 struct switch_tracking *switch_tracking)
183 {
184 if (event->header.type == PERF_RECORD_SAMPLE)
185 return process_sample_event(evlist, event, switch_tracking);
186
187 if (event->header.type == PERF_RECORD_COMM) {
188 int err, done = 0;
189
190 err = check_comm(switch_tracking, event, "Test COMM 1", 0);
191 if (err < 0)
192 return -1;
193 done += err;
194 err = check_comm(switch_tracking, event, "Test COMM 2", 1);
195 if (err < 0)
196 return -1;
197 done += err;
198 err = check_comm(switch_tracking, event, "Test COMM 3", 2);
199 if (err < 0)
200 return -1;
201 done += err;
202 err = check_comm(switch_tracking, event, "Test COMM 4", 3);
203 if (err < 0)
204 return -1;
205 done += err;
206 if (done != 1) {
207 pr_debug("Unexpected comm event\n");
208 return -1;
209 }
210 }
211
212 return 0;
213 }
214
215 struct event_node {
216 struct list_head list;
217 union perf_event *event;
218 u64 event_time;
219 };
220
add_event(struct evlist * evlist,struct list_head * events,union perf_event * event)221 static int add_event(struct evlist *evlist, struct list_head *events,
222 union perf_event *event)
223 {
224 struct perf_sample sample;
225 struct event_node *node;
226
227 node = malloc(sizeof(struct event_node));
228 if (!node) {
229 pr_debug("malloc failed\n");
230 return -1;
231 }
232 node->event = event;
233 list_add(&node->list, events);
234
235 if (evlist__parse_sample(evlist, event, &sample)) {
236 pr_debug("evlist__parse_sample failed\n");
237 return -1;
238 }
239
240 if (!sample.time) {
241 pr_debug("event with no time\n");
242 return -1;
243 }
244
245 node->event_time = sample.time;
246
247 return 0;
248 }
249
free_event_nodes(struct list_head * events)250 static void free_event_nodes(struct list_head *events)
251 {
252 struct event_node *node;
253
254 while (!list_empty(events)) {
255 node = list_entry(events->next, struct event_node, list);
256 list_del_init(&node->list);
257 free(node);
258 }
259 }
260
compar(const void * a,const void * b)261 static int compar(const void *a, const void *b)
262 {
263 const struct event_node *nodea = a;
264 const struct event_node *nodeb = b;
265 s64 cmp = nodea->event_time - nodeb->event_time;
266
267 return cmp;
268 }
269
process_events(struct evlist * evlist,struct switch_tracking * switch_tracking)270 static int process_events(struct evlist *evlist,
271 struct switch_tracking *switch_tracking)
272 {
273 union perf_event *event;
274 unsigned pos, cnt = 0;
275 LIST_HEAD(events);
276 struct event_node *events_array, *node;
277 struct mmap *md;
278 int i, ret;
279
280 for (i = 0; i < evlist->core.nr_mmaps; i++) {
281 md = &evlist->mmap[i];
282 if (perf_mmap__read_init(&md->core) < 0)
283 continue;
284
285 while ((event = perf_mmap__read_event(&md->core)) != NULL) {
286 cnt += 1;
287 ret = add_event(evlist, &events, event);
288 perf_mmap__consume(&md->core);
289 if (ret < 0)
290 goto out_free_nodes;
291 }
292 perf_mmap__read_done(&md->core);
293 }
294
295 events_array = calloc(cnt, sizeof(struct event_node));
296 if (!events_array) {
297 pr_debug("calloc failed\n");
298 ret = -1;
299 goto out_free_nodes;
300 }
301
302 pos = 0;
303 list_for_each_entry(node, &events, list)
304 events_array[pos++] = *node;
305
306 qsort(events_array, cnt, sizeof(struct event_node), compar);
307
308 for (pos = 0; pos < cnt; pos++) {
309 ret = process_event(evlist, events_array[pos].event,
310 switch_tracking);
311 if (ret < 0)
312 goto out_free;
313 }
314
315 ret = 0;
316 out_free:
317 pr_debug("%u events recorded\n", cnt);
318 free(events_array);
319 out_free_nodes:
320 free_event_nodes(&events);
321 return ret;
322 }
323
324 /**
325 * test__switch_tracking - test using sched_switch and tracking events.
326 *
327 * This function implements a test that checks that sched_switch events and
328 * tracking events can be recorded for a workload (current process) using the
329 * evsel->core.system_wide and evsel->tracking flags (respectively) with other events
330 * sometimes enabled or disabled.
331 */
test__switch_tracking(struct test_suite * test __maybe_unused,int subtest __maybe_unused)332 static int test__switch_tracking(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
333 {
334 const char *sched_switch = "sched:sched_switch";
335 const char *cycles = "cycles:u";
336 struct switch_tracking switch_tracking = { .tids = NULL, };
337 struct record_opts opts = {
338 .mmap_pages = UINT_MAX,
339 .user_freq = UINT_MAX,
340 .user_interval = ULLONG_MAX,
341 .freq = 4000,
342 .target = {
343 .uses_mmap = true,
344 },
345 };
346 struct perf_thread_map *threads = NULL;
347 struct perf_cpu_map *cpus = NULL;
348 struct evlist *evlist = NULL;
349 struct evsel *evsel, *cpu_clocks_evsel, *cycles_evsel;
350 struct evsel *switch_evsel, *tracking_evsel;
351 const char *comm;
352 int err = -1;
353
354 threads = thread_map__new(-1, getpid(), UINT_MAX);
355 if (!threads) {
356 pr_debug("thread_map__new failed!\n");
357 goto out_err;
358 }
359
360 cpus = perf_cpu_map__new_online_cpus();
361 if (!cpus) {
362 pr_debug("perf_cpu_map__new failed!\n");
363 goto out_err;
364 }
365
366 evlist = evlist__new();
367 if (!evlist) {
368 pr_debug("evlist__new failed!\n");
369 goto out_err;
370 }
371
372 perf_evlist__set_maps(&evlist->core, cpus, threads);
373
374 /* First event */
375 err = parse_event(evlist, "cpu-clock:u");
376 if (err) {
377 pr_debug("Failed to parse event dummy:u\n");
378 goto out_err;
379 }
380
381 cpu_clocks_evsel = evlist__last(evlist);
382
383 /* Second event */
384 err = parse_event(evlist, cycles);
385 if (err) {
386 pr_debug("Failed to parse event %s\n", cycles);
387 goto out_err;
388 }
389
390 cycles_evsel = evlist__last(evlist);
391
392 /* Third event */
393 if (!evlist__can_select_event(evlist, sched_switch)) {
394 pr_debug("No sched_switch\n");
395 err = 0;
396 goto out;
397 }
398
399 switch_evsel = evlist__add_sched_switch(evlist, true);
400 if (IS_ERR(switch_evsel)) {
401 err = PTR_ERR(switch_evsel);
402 pr_debug("Failed to create event %s\n", sched_switch);
403 goto out_err;
404 }
405
406 switch_evsel->immediate = true;
407
408 /* Test moving an event to the front */
409 if (cycles_evsel == evlist__first(evlist)) {
410 pr_debug("cycles event already at front");
411 goto out_err;
412 }
413 evlist__to_front(evlist, cycles_evsel);
414 if (cycles_evsel != evlist__first(evlist)) {
415 pr_debug("Failed to move cycles event to front");
416 goto out_err;
417 }
418
419 evsel__set_sample_bit(cycles_evsel, CPU);
420 evsel__set_sample_bit(cycles_evsel, TIME);
421
422 /* Fourth event */
423 err = parse_event(evlist, "dummy:u");
424 if (err) {
425 pr_debug("Failed to parse event dummy:u\n");
426 goto out_err;
427 }
428
429 tracking_evsel = evlist__last(evlist);
430
431 evlist__set_tracking_event(evlist, tracking_evsel);
432
433 tracking_evsel->core.attr.freq = 0;
434 tracking_evsel->core.attr.sample_period = 1;
435
436 evsel__set_sample_bit(tracking_evsel, TIME);
437
438 /* Config events */
439 evlist__config(evlist, &opts, NULL);
440
441 /* Check moved event is still at the front */
442 if (cycles_evsel != evlist__first(evlist)) {
443 pr_debug("Front event no longer at front");
444 goto out_err;
445 }
446
447 /* Check tracking event is tracking */
448 if (!tracking_evsel->core.attr.mmap || !tracking_evsel->core.attr.comm) {
449 pr_debug("Tracking event not tracking\n");
450 goto out_err;
451 }
452
453 /* Check non-tracking events are not tracking */
454 evlist__for_each_entry(evlist, evsel) {
455 if (evsel != tracking_evsel) {
456 if (evsel->core.attr.mmap || evsel->core.attr.comm) {
457 pr_debug("Non-tracking event is tracking\n");
458 goto out_err;
459 }
460 }
461 }
462
463 if (evlist__open(evlist) < 0) {
464 pr_debug("Not supported\n");
465 err = 0;
466 goto out;
467 }
468
469 err = evlist__mmap(evlist, UINT_MAX);
470 if (err) {
471 pr_debug("evlist__mmap failed!\n");
472 goto out_err;
473 }
474
475 evlist__enable(evlist);
476
477 err = evsel__disable(cpu_clocks_evsel);
478 if (err) {
479 pr_debug("perf_evlist__disable_event failed!\n");
480 goto out_err;
481 }
482
483 err = spin_sleep();
484 if (err) {
485 pr_debug("spin_sleep failed!\n");
486 goto out_err;
487 }
488
489 comm = "Test COMM 1";
490 err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
491 if (err) {
492 pr_debug("PR_SET_NAME failed!\n");
493 goto out_err;
494 }
495
496 err = evsel__disable(cycles_evsel);
497 if (err) {
498 pr_debug("perf_evlist__disable_event failed!\n");
499 goto out_err;
500 }
501
502 comm = "Test COMM 2";
503 err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
504 if (err) {
505 pr_debug("PR_SET_NAME failed!\n");
506 goto out_err;
507 }
508
509 err = spin_sleep();
510 if (err) {
511 pr_debug("spin_sleep failed!\n");
512 goto out_err;
513 }
514
515 comm = "Test COMM 3";
516 err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
517 if (err) {
518 pr_debug("PR_SET_NAME failed!\n");
519 goto out_err;
520 }
521
522 err = evsel__enable(cycles_evsel);
523 if (err) {
524 pr_debug("perf_evlist__disable_event failed!\n");
525 goto out_err;
526 }
527
528 comm = "Test COMM 4";
529 err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
530 if (err) {
531 pr_debug("PR_SET_NAME failed!\n");
532 goto out_err;
533 }
534
535 err = spin_sleep();
536 if (err) {
537 pr_debug("spin_sleep failed!\n");
538 goto out_err;
539 }
540
541 evlist__disable(evlist);
542
543 switch_tracking.switch_evsel = switch_evsel;
544 switch_tracking.cycles_evsel = cycles_evsel;
545
546 err = process_events(evlist, &switch_tracking);
547
548 zfree(&switch_tracking.tids);
549
550 if (err)
551 goto out_err;
552
553 /* Check all 4 comm events were seen i.e. that evsel->tracking works */
554 if (!switch_tracking.comm_seen[0] || !switch_tracking.comm_seen[1] ||
555 !switch_tracking.comm_seen[2] || !switch_tracking.comm_seen[3]) {
556 pr_debug("Missing comm events\n");
557 goto out_err;
558 }
559
560 /* Check cycles event got enabled */
561 if (!switch_tracking.cycles_before_comm_1) {
562 pr_debug("Missing cycles events\n");
563 goto out_err;
564 }
565
566 /* Check cycles event got disabled */
567 if (switch_tracking.cycles_between_comm_2_and_comm_3) {
568 pr_debug("cycles events even though event was disabled\n");
569 goto out_err;
570 }
571
572 /* Check cycles event got enabled again */
573 if (!switch_tracking.cycles_after_comm_4) {
574 pr_debug("Missing cycles events\n");
575 goto out_err;
576 }
577 out:
578 if (evlist) {
579 evlist__disable(evlist);
580 evlist__delete(evlist);
581 }
582 perf_cpu_map__put(cpus);
583 perf_thread_map__put(threads);
584
585 return err;
586
587 out_err:
588 err = -1;
589 goto out;
590 }
591
592 DEFINE_SUITE_EXCLUSIVE("Track with sched_switch", switch_tracking);
593